【Fujitsu】 OSIV/X8

 OSIV/X8(*) was one of the operating systems (hereinafter “OS”) for Fujitsu’s FACOM M series general-purpose computers, and was a large general-purpose OS positioned between super-large general-purpose OS OSIV/F4 and medium general-purpose OS OSIV/F2. The OS was announced in September 1975.
 OSIV/X8 was developed with the aim of supporting a broad range of computer systems from medium-scale to large-scale, maintaining upper compatibility with OSII/VS, which was the OS for the FACOM 230-8 series. In addition, OSIV/X8 aimed for applying the functions and performance of a large-scale system to medium-scale systems without significantly degrading such functions and performance. To achieve these goals, the company devised a variety of ideas for realizing a virtual memory control, with keeping the basic structure of the control program compliant with OSIV/F4. Fujitsu completed a batch function in October 1977, and a remote batch processing function (RES: Remote Entry Services) and online database AIM (Advanced Information Manager) in March 1978. Then OSIV/X8 enabled the user of OSII/VS of the FACOM 230-8 series to transfer the operating assets (program, data file, job procedure, etc.) to the M series, with securing compatibility between the two series. And the users enjoyed also the new hardware and software of the M series. .
 OSIV/X8 was succeeded by OSIV/X8 FSP, which was announced in February 1983.
 The following describes the features of OSIV/X8, its major functions and functional enhancements.

*: OSIV/X8 was pronounced “OS four X eight” The letters “OSIV” were represented 4th generation OSs, and were added to the heads of the names of all OSs for the FACOM M series computers.

1. Features of OSIV/X8

 OSIV/X8 had the following features:

(1) Achievement of multidimensional simultaneous processing
 OSIV/X8 was a large general-purpose OS positioned between OSIV/F4 and OSIV/F2, and achieved simultaneous execution of different types of processing such as batch processing, remote batch processing (RES), interactive processing (TSS: Time Sharing System), online database processing (AIM) and distributed processing.
(2) Support for a wide range of system sizes
 The OS supported a wide range of system sizes, from the lowest model to the highest model of the FACOM M-100 series, and from 256 KB main memory to 16 MB main memory. 16 MB was the maximum main memory capacity of super-large model FACOM M-190 at the time of the OSIV/X8 announcement.
(3) Provision of online database AIM (Advanced Information Manager)
 Fujitsu categorized the functions required for establishing an online database into subsystems, and provided the new online database AIM consisting of the subsystems. AIM achieved expandability and flexibility of the system together with ease of system development and operation.
(4) Provision of OSII/VS compatible functions
 The OS maintained compatibility with OSII/VS in terms of application program’s source program, files and job control statement, in order to ensure effective use of the software assets of the users. In addition, the OS enabled OSII/VS’s application program load module to operate using an integrated emulator (OSII/VS compatible executor).
2. Major functions of OSIV/X8

 OSIV/X8 had the following functions:

(1) Up to 255 virtual memory address spaces
 OSIV/X8 adopted a multiple virtual memory control that enabled the OS to have up to 255 virtual address spaces, allowing each space to hold 16-MB virtual memory.
 Meanwhile, adoption of a multiple virtual memory control similar to that of the super-large OS OSIV/F4 increased the required main memory capacity of the OS. That was a major issue to have to be solved for OSIV/X8 which was also intended to be applied to medium-scale systems. To solve this problem, the company devised various ideas for realizing a multiple virtual memory control. In addition to ordinary LRU (Least Recently Used) control, the OS fed the state of transition of program control on the virtual memory back to the page replacement logic to advance effective use of the main memory. The new control employed two types of controls. One was VS overlay control for the control program area, and another was roll-in/roll-out control for the ordinary job area.
(2) Online database AIM
 With AIM, Fujitsu categorized the functions required to build an online database into the following five types, and provided corresponding software components:
- Message control (DCMS: Data Communication Management Subsystem)
- Database management (DBMS: Data Base Management Subsystem)
- Operation management (ISMS: Integrity and Schedule Management Subsystem)
- Asset management of the AIM system (DDMS: Dictionary and Directory Management Subsystem)
- Support function (utilities)
 The user was able to easily create application programs using software components of AIM.
(3) Operability
 OSIV/X8 provided functions for increasing operability, such as job scheduling functions (job group control, job control macro, multiple calls of macro and override function, etc.), a function for easily generating the optimal OS suitable for the required system size, and a center operation function SMF (System Management Facilities). In addition, the OS provided functions for improving operability, such as an operation instruction macro function, a function for facilitating interaction with the operator through use of a light pen and a function key, and a dynamic status indication function for displaying the job execution status and the resource utilization status, using a color display device as the console.
3. Functional enhancements of OSIV/X8

 Following the announcement of OSIV/X8 in September 1975, functions of the OS were enhanced and new software was provided. The following table shows major functional enhancements.

Table: Functional enhancements of OSIV/X8
Announcement date Major features Edition Shipment date
September 1975
・Announcement of large general-purpose OS OSIV/X8
-Control program, TSS, AIM, HICS, language processing programs, service programs
October 1977 to March 1978
April 1979 E30 June 1980
October 1979
・Provision of new software
-Programs AIF (*1), GEM (*2) and AIDS (*3), which increased ease of use in an interactive manner
-Tool AOF (*4) for automated/labor-saving operation
-Data retrieval system DQS (*5) focused on the end user, tool STAFF/X for outputting a report
E30B October 1980
October 1980
・Provision of software that increased productivity
-High-productivity language HYPER COBOL, development tool ACS(*6), automatic specification document creation PAGE(*7)
・Provision of end user-oriented interactive integrated system INTERACT (QUERY, SPEAKEASYIII, STAFF/X)
E40 October 1981
February 1983
・Support of JEFII
E40 October 1984
*1 AIF:Advanced Interactive processing Facility
*2 GEM:Generalized program Editing and Management Facility
*3 AIDS:AIM Information Display Support System
*4 AOF:Advanced Operation Facility
*5 DQS:Display Based Query System
*6 ACS:Application Control Support System
*7 PAGE:Program Specification Auto GEnerator